pvsvoc

pvsvoc —
Combine the spectral envelope of one fsig with the excitation (frequencies) of another.

Description

This opcode provides support for cross-synthesis of amplitudes and frequencies. It takes
the amplitudes of one input fsig and combines with frequencies from another. It is a spectral
version of the well-known channel vocoder.

Syntax

fsig pvsvoc famp, fexc, kdepth, kgain [,kcoefs]

Performance

fsig -- output pv stream

famp -- input pv stream from which the amplitudes will be extracted

fexc -- input pv stream from which the frequencies will be taken

kdepth -- depth of effect, affecting how much of the frequencies will
be taken from the second fsig: 0, the output is the famp signal, 1 the output is the famp
amplitudes and fexc frequencies.

kgain -- gain boost/attenuation applied to the output.

kcoefs -- number of cepstrum coefs used in spectral envelope estimation (defaults to 80).

Warning

It is unsafe to use the same f-variable for both input and output of pvs opcodes. Using the same one might lead to undefined behavior on some opcodes. Use a different one on the left and right sides of the opcode.

The example above shows a typical cross-synthesis operation. The input signal (say a vocal sound) is used for its amplitude spectrum. An oscillator with an arbitrary complex waveform produces the excitation signal, giving the vocal sound its pitch.